//
   //  ========================================================================
   //  Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd.
   //  ------------------------------------------------------------------------
   //  All rights reserved. This program and the accompanying materials
   //  are made available under the terms of the Eclipse Public License v1.0
   //  and Apache License v2.0 which accompanies this distribution.
   //
   //      The Eclipse Public License is available at
  //      http://www.eclipse.org/legal/epl-v10.html
  //
  //      The Apache License v2.0 is available at
  //      http://www.opensource.org/licenses/apache2.0.php
  //
  //  You may elect to redistribute this code under either of these licenses.
  //  ========================================================================
  //
  
  package org.eclipse.jetty.websocket.common.extensions.compress;
  
  import java.nio.ByteBuffer;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.eclipse.jetty.util.BufferUtil;
  import org.eclipse.jetty.websocket.api.MessageTooLargeException;
  
  public class ByteAccumulator
  {
      private final List<Chunk> chunks = new ArrayList<>();
      private final int maxSize;
      private int length = 0;
  
      public ByteAccumulator(int maxOverallBufferSize)
      {
          this.maxSize = maxOverallBufferSize;
      }
  
      public void addChunk(byte buf[], int offset, int length)
      {
          if (this.length + length > maxSize)
          {
              throw new MessageTooLargeException("Frame is too large");
          }
          chunks.add(new Chunk(buf, offset, length));
          this.length += length;
      }
  
      public int getLength()
      {
          return length;
      }
  
      public void transferTo(ByteBuffer buffer)
      {
          if (buffer.remaining() < length)
              throw new IllegalArgumentException();
          int position = buffer.position();
          for (Chunk chunk : chunks)
          {
              buffer.put(chunk.buffer, chunk.offset, chunk.length);
          }
          BufferUtil.flipToFlush(buffer, position);
      }
  
      private static class Chunk
      {
          private final byte[] buffer;
          private final int offset;
          private final int length;
  
          private Chunk(byte[] buffer, int offset, int length)
          {
              this.buffer = buffer;
              this.offset = offset;
              this.length = length;
          }
      }
  }